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Thomas.londrigan Thomas.londrigan Presentation Transcript

  • Bigelow Aerospace GenesisTesting Expandable Spacecraft in LEO Tom Londrigan Mission Operations Manager Bigelow Aerospace Used with Permission
  • Bigelow Aerospace Company OverviewBigelow Aerospace is a privately owned company dedicated to developing low-cost, next-generation crewed space complexes.Facilities and personnel – Currently 95 personnel • Seeking qualified engineers – Main facility in North Las Vegas • 500,000 Square foot assembly facility • Fabrication capabilities for all modules • Mission Control facility • Ground communication assets • Radiation exposure facility (LDRS) onsite – Office in Washington D.C. 2
  • GenesisThe Genesis program utilizes space vehicles in Low Earth Orbit with the objective of testing and validating the technologies necessary for the deployment of expandable space habitats 3
  • GenesisThe Genesis program consists of two small scale prototype spacecraft, currently in orbit Genesis 1 – Launched July 12, 2006 Genesis 2 – Launched June 28, 2007 4
  • Mission ProfileOrbital Parameters 583x556 km, 64.5 deg inclination – Nominal 10 year mission orbital decayNominal Aft earth facing orientation – Gravity gradient fallacy – more on this laterInsertion on Dnepr Launch Vehicle – Silo launched – SS-18 ICBM Modified for small satellite insertion – Final Spacecraft integration occurred at Dombarovsky facilityGenesis launched inert, Auto activation on separationNo re-boost capability 5
  • Mission ObjectivesPrimary Objective – Demonstrate Inflation and Deployment in LEOSecondary Objectives – Develop core competency to build, launch and operate satellites and space complexes – Proof of concept for folding, restraint, and core structure – Evaluate the Durability of soft goods – Long term Effectiveness of the MMOD shieldTertiary (Mission Creep) Objectives – Revenue and interest-generating payloads – Evaluate the performance of various off-the-shelf (literally) electronic components – Obtain long term evaluation of power systems – Evaluate radiation environment 6
  • Genesis Spacecraft description Internal core structure, surrounded by inflated volume– Battery and payloads in interior of spacecraft– Some avionics contained on exterior of the core structure– Launch adapter on aft end 7
  • Genesis Spacecraft descriptionMMOD shield description – Multi-layer insulation with interstitial foam to provide loft – Restraint layer – load bearing – Air Barrier – Folded in launch configuration, restrained with strapsDeployment systems – Retention straps released using pyro cutters • Contingency - Retention straps sized to fail/release due to expansion forces – Solar array deployment – All deployment and inflation controlled by onboard flight computer 8
  • Genesis PayloadsGenebox - Genesis 1 – Small payload from Ames – Objective was to test sensors and optical systems for GeneSatRadiation Monitors – Dose Depth Monitors • RadFETs to measure cumulative energy deposition – Proton Monitors • Single Event Upset measurement 9
  • Genesis PayloadsLogos – some demonstration, some paying customers“Fly-Your-Stuff” program – Small objects and cards – Allow private individuals to fly small objects in space verified by downlinked photos – Approximately 80 customers 10
  • Genesis SystemsInflation – Genesis 1 : Single tank, redundant solenoid valves – Genesis 2 : 4 tanks, 1 solenoid valve eachPower – 8 Solar array “wings”, single battery with redundant charge regulators – Solar array capacity was intentionally over-designed, with partial capability available even in deployment failure. – Solar arrays were designed to be tolerant of solar incident angleCommunications – Redundant omni-directional antennae on each end of spacecraft – UHF/VHF for duplex command and telemetry – S-band for photo downlink 11
  • Genesis SystemsTelemetry – Genesis 1 – 1172 data parameters – Genesis 2 – 1830 data parameters – All data is recorded onboard the spacecraft and downloaded as encrypted files during passes over ground sites – Data sampling rate can be scaled up and down as necessary to prevent build up of data – Real time data points can be obtained by direct query while in communication coverage – Data is collected and archived at the Las Vegas site 12
  • Genesis SystemsCameras – Genesis 1: 18 cameras for internal and external evaluation of softgoods, some oriented on payloads – Genesis 2 : 22 cameras for internal and external evaluation of softgoods • Mounted on solar arrays (4) for observing softgoods and capturing projector images • Interior Pan-Tilt-Zoom cameras operable from ground • Wireless deployable camera on exterior of MMOD shielding • Some oriented on internal payloads • Fisheye and Narrow field of view mounted on ends 13
  • Genesis CamerasAft mounted cameras provided earth observations – minimum resolvable distance 0.25 miles 14
  • Genesis SystemsProjectors – Off the shelf from the local electronics store, modified only enough to allow remote commanding and mounting – Placed on aft and forward solar array ends to project images onto exterior 15
  • Attitude Control SystemsMission Design provided very forgiving pointing requirements – Nadir aft orientation and rotation about long axis provided a benign thermal environment – ‘rotisserie’ effect – RF link margin and antenna radiating patterns allowed for comm. from almost all anglesHardware – Magnetometers • 2 mounted in forward end – Sun Sensors • 4 on forward structure – Magnetic torque rods • 2 mounted in X (longitudinal) axis • One each mounted in Y, Z axes 16
  • Ground Station NetworkDescription of Ground communications architecture – For Genesis 1 launch, VA and NV ground stations only – UHF, VHF uplink capability – 6-meter S-band dish – Some leased sites, however all assets are the property of Bigelow Aerospace 17
  • Ground StationsSetup and commissioning of new ground stations – For Genesis 2 launch added AK, HI sites – Shifted VA ground station to Maine and added S-band dish 18
  • Future Ground sitesAdditional Ground sites are planned to increase coverage on future missions 19
  • De-OrbitDe-orbit Analysis – Current orbital lifetime is estimated to be 12 years • We are examining the drag models and refining estimates on a monthly basis – Object Reentry Satellite Analysis Tool (ORSAT) de-orbit analysis from April 2004 • Parent body and Fragmentation analysis • All structural components predicted to demise upon re-entry 20
  • Spacecraft Construction and TestingSpacecraft assembly occurred at Nevada facility, followed by shipment to Russia.Final checkout at launch base, then turned over to Kosmotras for integration onto the space head module – ITAR at the time necessitated stringent restrictions for launch base ops and plans for recovery of possible launch failure.Applying design updates in an accelerated design cycle between Genesis 1 and 2 – Integration begun less than six months after launch of Genesis 1 - 6 months before scheduled ship dateLimitations of Facilities and equipment on testing – Most equipment bench tested but bare bones approach prevents a large amount of testing systems for end to end testing – Difficulties in fully testing ACS sensors, radio systems in flight configurationRisk tradeoffs/ Risk acceptance – Ultimately for Genesis 1 and 2, there was just one paying internal customer, who was willing to evaluate and accept risks 21
  • Overview of Genesis 1 and 2 operationsCreating Mission Operations from scratch – all prior efforts had been on building the spacecraft – Creating plans – as basic as establishing chain of command for decision making – Establishing procedures where there are none • flight rules – discuss prior to eliminate real-time debate, Etc. 22
  • Genesis OperationsFirst contact – planning for contingences on an experimental spacecraft – Minimal ground assets in place, spacecraft tumbling which complicated contact • Effectively, contact time was 2-3 minutes – Needed to perform quick health and status evaluations – Downlink photos to satisfy THE customer – Verify all functions of automated sequence – Nominal tipoff rate of insertion was <2 RPM – we got better than this but ACS system was not fully operational – no stability for the first weekFollow-on operations – We are holding pressure – pictures are pretty, now what? – Examining the inflation sequence and increasing pressure – Downloading complete data sets, all photo documentation 23
  • ResultsBoth Spacecraft have performed flawlessly on primary objective – inflation and deploymentPower Consumption – battery performance was within design tolerances – No appreciable solar array degradation in capacityInflation results – stable pressure with no leakageThermal – Genesis provided data and analysis of the soft goods performance in an orbital environmentCommunications – this mission provided spaceflight heritage for radios which are planned to fly on future missions 24
  • Lessons Learned from Genesis 1In God we trust, all others bring data – rapid build process had not captured test data – If it is not documented, it did not happenACS – not all disturbance torques were captured in first analysis – Rapid integration of the algorithm resulted in constant on of torquers • ACS system had to be reconfigured on orbit – Initial ‘gravity gradient’ fallacy – other disturbance torques proved dominantIdentified need for baseline testing and documentation – compressed schedule did not allow for validation of as built configurationThermal sensors were few, and sensor placement needed better documentation 25
  • Applications to Genesis 2Implemented test plansEstablished Pre-ship review processIncreased thermal sensors and thoroughly documented placement on spacecraft – Placed thermal sensors within the MMOD shielding – Modeled the sensor placement with CAD programsDocumented all test data for comparison on orbit – Mission Operator input was used to create new formats and cataloguing of data 26
  • Genesis 2 Initial OpsWhat we improvedOperations – Established and validated procedures on Genesis 1 – Validated all Genesis 2 procedure delta’s during testing – Better communication plans – Baseline testing allowed better system performance evaluation – ACS system algorithms debugged • Checklist for activation rather than turning it on • When we turned the ACS system on, communications stabilized within 48 hours 27
  • Lesson Learned from Genesis 2Mission Data Analysis – empirical data for LEO – Thermal Data – Radiation Data – Drag Analysis – performing model comparisons, essential for future vehicles • Continuing ongoing analysis shows some unexpected data not fully modeled – Example: eccentricity of orbit fluctuating – counter-intuitive to the drag model • Long term effort using Two Line Element and tracking data to evaluate orbital lifetimeIdentified the need for a high fidelity ground analog vehicle for testing 28
  • Obstacles to OvercomeLimitations on ground station access – all operations become time criticalITAR restrictionsMinimizing expenditure on ground infrastructure while using only proprietary assetsGenesis systems were simple but most lessons learned were procedural – problems will be preventedMaintain highly creative, innovative atmosphere while creating more rigorous processesNo acceptance criteria (at first)Overcome ‘Not invented here’ mentality 29
  • Applications to future spacecraftFuture vehicles – Sundancer • Crewed module • Engineering proof of concept • Approximately 180 m3 – BA Standard • Full size module ~300 m3 • Capable of 3 crew – Propulsion Bus • Attached node for complex assembly • Reboost and resupply capability 30
  • Questions?Tom Londrigan702-639-4440tlondrigan@bigelowaerospace.comwww.bigelowaerospace.com 31